Discharge valves

The most accurate flow rate control can be achieved by using the loss-in-weight method. The total amount of material required for a downstream process is first added to a tank or hopper scale. As the material is discharged, the loss-in-weight is monitored and used to modulate the discharge valve or gate to achieve the desired flow rate. 

A thorough sampling plan should describe when the sample is to be taken and how many samples are required. It also specifies from what location within the equipment, such as the manway or discharge valve, to take the sample. The plan should also indicate what sampling equipment and sample container should be used, as well as the type of tests to be performed and the acceptance criteria. 

The latter is generally necessary for devices with long travel times, such as flush-fitting reactor discharge valves that are motor-driven. 

Figure 10-48 is a direc t-acting pump, designed for use at pressures up to 0.690 MPa (100 Ibfiin"). In this figure, the piston consists of disks A and B, with packing rings C between them. A bronze liner for the water cyhnder is shown at D. Suction valves are Ei and Eo. Discharge valves are Fi and Fo. 

Pressure and vacuum sealed product discharge valve... 

FIG. 18-44 High-intensity mixer (a) bottom scraper (h) fluidizing tool (c) horn tool (d) flush-mounted discharge valve. Henschel Mixers America, Inc.)... 

Provide for addition of diluent, poison, or inhibitor directly to reactor. Provide for automatic or manual actuation of bottom discharge valve to drop batch into a dump tank with diluent, poison or inhibitor, or to an emergency containment area. 

This condition cannot be corrected on pumps with an enclosed impeller. You need to relax the restricted discharge flow on the pump. The problem could be a clogged downstream filter, a closed discharge valve, an over-pressurized header (back-pressurizing the pump), or a... 

Hf system valves = Hf suction valves + Hf discharge valves... 

Compensates Operational Praetiees - It s a common practice in many plants to close or throttle a discharge valve with the pump running to meter the flow through the pipes. 

No discharge pressure. Pump improperly primed. Inadequate Speed. Not enough NPSHa. Plugged impeller or piping. Incorrect rotation. Closed discharge valve Air aspirated or air pockets at the suction line. 

The expander is now ready to be put into operation. Open the compressor inlet valve and expander discharge valve simultaneously. Then open the compressor discharge valve. Make sure the variable nozzles are in the closed position. Push the start button on the control panel to open the inlet shutdown valve. 

Glycol powered pump. Close the dry discharge valve and see if the pump continues to run if so, the pump needs to be repaired. 

V = average gas velocity, fpm Pd = piston displacement per cylinder, ft /min A = total inlet or discharge valve area per cylinder, in. ... 

The area. A, is the product of actual lift and the valve opening periphery and is the total for all inlet or discharge valves in a cylinder. The lift is a compressor vendor-furnished number. 

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